DE102013005633B4 - Production of microstructures in microsystems - Google Patents

Abstract

Artificial hair cell sensor (10) having • a microchannel (22); A growth channel (30) in communication with the microchannel (22); A metallic hair element (14) arranged in the growth channel (30) and projecting upwards from the growth channel (30) on a microsystem surface (28) of the hair cell sensor (10); An integrated microproduction device (12), which has a material separation device with a cathode (16) and an anode (18), the material separation device being adapted for further metal (20) in the microchannel (22) for regrowth of the hair element (14) to be deposited galvanically at the bottom; An ejection or ejection device (24) for ejecting or expelling the regrowing hair element (14) through the growth channel (30) upwards, wherein the growth channel (30) is designed such that the hair element (14) at an outlet opening (26) the microsystem surface (28) emerges out of the growth channel (30), • a force sensor for measuring the force acting on the hair element (14), which exerts a torque on the hair element (14) and thereby a curvature at the outlet opening (26) causes.

Description

The present invention relates to a microsystem.

Microsystems are typically systems of the order of millimeters, usually containing microstructures on the order of μm, which interact in one system, allowing for several different areas of physics, such as electronics and optics, electronics and mechanics, fluidics and biochemistry.

In the production of microsystems MEMS (Microelectromechanical Systems) techniques are often used. The microstructures of the microsystems can be very sensitive and easily destroyed during further processing and / or assembly.

The present invention is therefore based on the object of reducing or even eliminating the possibility of damage or destruction of a microstructure during further processing and / or assembly.

This object is achieved by a microsystem with an integrated microproduction device for preferably controlled production of a microstructure. For example, the production or production of a microstructure can take place as needed (on demand) and / or on site (on site), in particular during operation (in operation).

According to a particular embodiment of the invention it can be provided that the micro-production device is designed for automated production of the microstructure with a predetermined geometry and / or function after activation. Activation can be effected, for example, by switching on the microproduction device before or after installation or before or during operation of the microsystem. It can be done for example by a person and / or a remote control, but also by environmental conditions.

Alternatively, the micro-production device for automated production of the microstructure may be designed with an initial set or definable geometry and / or function during activation of the microsystem after activation. The type of geometry and / or the function can thus be determined in this embodiment, for example, only during operation, for example, depending on the environmental conditions. Within certain limits, the type of microstructure or the specific embodiment of the microstructure can thus only be defined during operation. As a result, the microsystem can be adapted for different tasks.

The microsystem has a transport means, such as a translator, for transporting the microstructure.

Furthermore, the microsystem may have a sensory, actuatoric, fluidic, optical and / or magnetic function.

The microstructure is an artificial hair element. The resulting microsystem then has the function of a hair cell sensor (artificial hair cell sensor (AHCS).) In particular, a mechanical hair cell sensor with a regeneration-capable sensing element can thus be realized.

In particular, the microproduction device may contain a preferably electrochemical material deposition device, in particular a device for galvanic deposition or electroless deposition. Alternatively, the micro-production device may comprise a material hardening device, in particular a device for solidifying LCP (liquid crystal polymer) material.

According to a particular embodiment of the invention, the material separation device or the material hardening device is designed to simultaneously expel or push out the hair element from a microsystem surface. For example, in the Materialabscheide- or material hardening process feed forces arise, so that the generation of the hair element or more generally the microstructure and the advancing (such as ejection or expulsion), for example, from an exit point combined.

Alternatively, it is conceivable that the microsystem contains an ejection or ejection device, in particular an actuator, for preferably partial ejection or expulsion of the hair element from a microsystem surface.

In particular, a stamp may be provided, which is driven by a piezoelectric, an electrostatic or a thermal actuator according to the inchworm principle.

Furthermore, it can be provided that the microsystem has a force sensor for measuring the force on the root of the hair element.

Advantageously, the force sensor is a capacitive sensor, in particular between the hair element and a counter electrode, or a piezoresistive sensor.

Finally, according to a particular embodiment, the microsystem has a touch sensor and / or flow sensor function. In other words, then the artificial hair element is used to determine and possibly also quantify a touch and / or flow.

The invention is based on the surprising finding that by providing a microproduction device in a microsystem, the production or production of a microstructure can be postponed in time, namely to a time after further processing and / or assembly. As a result, you can then install the microstructure in a semi-finished, which may then be subjected to mechanical stress, since the sensitive parts develop only after assembly.

Furthermore, at least in one particular embodiment, the present invention provides for the first time a microsystem which can not build itself up during operation.

However, the present invention provides not only microsystems with "growing" microstructures, but also with regenerative microstructures. In addition, due to the temporal shifting of the production of the microstructure, its geometry and / or function can be left incompletely predefined and only completely determined during operation, for example as a function of the task then to be performed.

After a destruction of the microstructure, the function of the microsystem can be restored by regeneration thereof, for example based on a hair cell sensor "regrowth" of the hair element thereof.

The microstructures may, for example, be a hair element, but also, for example, a surface structure for influencing the flow, for example microstructures on a surface that flows around, which can reduce the drag coefficient of the flow and make the growth of parasites difficult (shark skin effect), microstructures on surfaces, which prevent the accumulation of dirt particles (lotus effect), and diffractive elements of micro-optics, which can focus and control light act. In the case of the diffractive elements of the micro-optics, a targeted influencing of a light beam takes place through a regular arrangement of microstructures. For example, you can build a microsystem that performs an optical task that needs to be precisely defined after integration into an overall system.

Further features and advantages of the invention will become apparent from the appended claims and the following description in which several examples are explained in detail with reference to the schematic drawings. Showing:

1 a sectional view of a microsystem according to a first particular embodiment of the present invention;

2 a sectional view according to a second particular embodiment of the present invention;

3 a sectional view of a third, not claimed embodiment and

4 a sectional view of a fourth, not claimed embodiment.

The following description relates to four different microsystems. These are all hair-hair sensors.

Hair cell sensors could not prevail in practice because they have a big disadvantage: the sensitive hair elements (hair) can break off easily. As natural hair regrows, the known micromechanical hair cell sensors are destroyed when the sensor hair breaks or breaks. With the present invention, it is now possible to build sensor chips in which a sensor hair is not patterned in the manufacture of the chip, but later grows out of the chip. For this purpose, a nozzle may be provided in the chip, in which the material of the hair is synthesized and solidified. From this nozzle, the hair is pushed out and thus grows out of the chip. This can, for example, occur very slowly continuously, or the growth is initiated once, for example, and then repeated as needed (when the hair breaks).

Among other things, the present invention provides a microsystem from which a hair grows out during operation. The hair can be used, for example, for sensory tasks. For this purpose, sensor elements (transducers, that is to say elements which convert a physical variable into an electrical signal) can be applied to the hair or to the hair root. These may be, in particular, mechanical sensor elements which measure the curvature of the hair near the root of the hair, which is effected by a deformation imposed externally on the hair. Such sensor structures may be, for example: strain gauges (piezoresistive elements), capacitive sensors, piezoelectric sensors, pressure-sensitive layers (for example carbon nanoparticles), optical sensors, thermal sensors and sensors that use the tunneling effect.

The hair may be made of, for example, metal, a semiconductor material or an insulator material, for example of polymer or plastic.

The material for the growth of the hair is preferably supplied as a liquid or stored in a chip. However, the supply / storage in the gas phase or as a solid are also conceivable.

• – elektrochemische (galvanische) oder stromlose Abscheidung aus der Flüssigphase.
• – Mischung von zwei Substanzen, die sich dann verfestigen, durch zwei mikrofluidische Kanäle. Strömung eines Materials (Harz) durch eine Düse, bei der durch einen kleinen mikrofluidischen Seitenkanal ein Verfestiger (Härter) beigemischt wird. Verfestigung durch Polyaddition, Polykondensation oder Polymerisation.
• – Erzeugung von Methylmethacrylat,
• – Erzeugung von Fibrin,
• – durch ultraviolettes Licht induzierte Verfestigung,
• – Abscheidung von Flüssigkristallen.

The following possibilities are conceivable for the solidification of a liquid:

• - Electrochemical (galvanic) or electroless deposition from the liquid phase.
• - Mixture of two substances, which then solidify, through two microfluidic channels. Flow of a material (resin) through a nozzle, in which through a small microfluidic side channel a solidifier (hardener) is added. Solidification by polyaddition, polycondensation or polymerization.
• - production of methyl methacrylate,
• - production of fibrin,
• Ultraviolet light-induced solidification,
• - Separation of liquid crystals.

• – Kleine Linearaktoren, die in dem Kanal, in dem das Haar verankert ist und aus dem es herausgeschoben wird, angebracht werden. Diese können als elektrostatische oder thermische Inchworm-Aktoren ausgeführt sein. Beim Inchworm-Aktor ist der Aktor mit dem Haar nicht fest verbunden. Er bewirkt in einem Zyklus nur einen sehr kleinen Weg (μm oder nm). Die Wege addieren sich jedoch durch viele Zyklen zu einer makroskopischen Bewegung.
• – Ein Linearaktor kann von unten als Stempel in die Düse eindrücken und das Haar vorwärts treiben. Auf dem Stempel kann eine UV-Lichtquelle integriert sein oder der Stempel kann UV-transparent sein, so dass durch den Stempel UV-Licht in die Düse gelangen kann.
• – Unterhalb der Düse kann ein Druck erzeugt werden, der eine Kraft auf das Haar nach außen bewirkt.
• – Es können Schichten zum Einsatz kommen, die bei der Verfestigung Druck aufbauen, der das Haar aus der Düse nach außen bewegt. Dies kann insbesondere durch ein Material mit anisotroper Struktur, wie zum Beispiel Flüssigkristall, geschehen. Der Aufbau des Drucks kann durch eine gezielte Ausrichtung der Kristallite des Flüssigkristalls gefördert werden.

The ejection or expulsion of the hair can be effected inter alia by the following methods:

• - Small linear actuators mounted in the channel where the hair is anchored and pushed out. These may be embodied as electrostatic or thermal inchworm actuators. With the inchworm actuator, the actuator is not firmly connected to the hair. It causes only a very small path (μm or nm) in one cycle. However, the paths add up to a macroscopic movement through many cycles.
• - A linear actuator can press from below as a punch in the nozzle and drive the hair forward. A UV light source can be integrated on the stamp or the stamp can be UV-transparent, so that UV light can enter the nozzle through the stamp.
• - Below the nozzle, a pressure can be generated, which causes a force on the hair to the outside.
• - Layers can be used which build up pressure during solidification, which moves the hair out of the nozzle. This can be done in particular by a material with anisotropic structure, such as liquid crystal. The structure of the pressure can be promoted by a targeted alignment of the crystallites of the liquid crystal.

In the following, only microsystems exemplified are described according to particular embodiments of the present invention:
All embodiments described below have in common that in principle they have a device for producing a hair element (hair) and a force sensor and, if necessary, also a separate actuator for ejecting or pushing out the hair element.

This in 1 shown microsystem 10 has an integrated microproduction facility 12 for the controlled production of a microstructure in the form of a hair element 14 on. The microproduction facility 12 has a device for galvanic material deposition. This includes a cathode 16 and an anode 18 , On the metallic hair element 14 , For example, made of nickel, by means of the device for galvanic deposition from below galvanic in a microchannel 22 another metal 20 deposited. The electrolyte used in the electrodeposition can be supplemented by the removal of a sacrificial electrode (not shown).

In addition, the microsystem has an ejector in the form of an electrostatic inchworm actuator 24 for pushing or pushing out the hair element 14 like a growing or regrowing hair from an outlet 26 in a microsystem area 28 on. Said inchworm actuator 24 surrounds a part of the hair element 14 in a growth channel 30 that with the outlet 26 is in fluid communication.

An external force generates a torque on the hair element. This torque in turn causes a curvature at the point where the hair element exits the channel. The curvature of the hair cell 14 For example, by means of a capacitive sensor between the hair cell 14 and a counter electrode 27 be measured.

At the in 2 In the embodiment shown, the growth and the Aktorik as in in 1 shown embodiment separated. In other words, that has in 2 shown microsystem 32 also via a microproduction facility 34 and an additional or ejection or ejection device in the form of a stamp 36 the piezoelectric from below against freshly grown hair element material 38 is pressed and the hair element 14 through the growth channel 40 pushes outward.

The microproduction facility 34 is designed to be two starting materials 42 and 44 through separate microchannels 46 respectively. 48 a growth zone 50 be fed liquid, to cure. With the starting materials 42 and 44 it can be a so-called two-component system. This then hardens chemically. Alternatively, for example, a polymer could be used that is cured, for example, thermally or by UV light from an LED (not shown) or a light pipe (not shown).

The sensor system may, for example, have a spring structure that is created by etching a pit 47 next to the growth channel 40 arises. The deformation of the spring structure, for example, by a piezoresistive material 49 to be measured in the pit.

The embodiments according to the 3 and 4 differ from the embodiments according to the 1 and 2 essentially, in that they combine growth and actuators.

In the microsystem 52 according to the 3 no separate ejection or Ausschiebeeinrichtung is provided, but so to speak in the micro-production facility 54 contain. The latter has a device for electroless deposition. The electroless deposition is thereby by catalytic coating 56 below the hair element 14 limited. The feed or the ejection / expulsion of the hair element 14 from the outlet 58 in the growth channel 60 done by the stress of the growing metal 62 induced.

The sensor, for example, again a capacitive sensor with a counter electrode 57 like the microsystem according to the 1 exhibit.

The microsystem 64 from 4 has a microproduction facility 66 on. By means of the latter, a liquid crystalline polymer 68 locally solidified. When an electric field is applied across an anode 72 and a cathode 70 For example, the anisotropic microstructure of the liquid crystalline polymer results in a directional force as indicated by the arrows 74 implied that the hair element 14 pushes outward.

The sensor system may include, for example, a piezoresistive sensor.

The features of the invention disclosed in the foregoing description, in the drawings and in the claims may be essential both individually and in any desired combinations for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

10

microsystems

12

Micro production facility

14

hair element

16

cathode

18

anode

20

metal

22

microchannel

24

Inchworm actuator

26

outlet opening

27

counter electrode

28

Micro System Design

30

growth channel

32

microsystems

34

Micro production facility

36

stamp

38

Hair element material

40

growth channel

42, 44

starting materials

46

microchannel

47

pit

48

microchannel

49

piezoresistive material

50

growth zone

52

microsystems

54

Micro production facility

56

coating

57

counter electrode

58

outlet opening

60

growth channel

62

metal

64

microsystems

66

Micro production facility

68

polymer

70

cathode

72

anode

74

force

Claims (2)

Artificial hair cell sensor ( 10 ) with • a microchannel ( 22 ); • one with the microchannel ( 22 ) related growth channel ( 30 ); • one in the growth channel ( 30 ) and on a microsystem surface ( 28 ) of the hair cell sensor ( 10 ) from the growth channel ( 30 ) upwardly projecting metallic hair element ( 14 ); • an integrated micro-production facility ( 12 ) comprising a material separation device with a cathode ( 16 ) and an anode ( 18 ), wherein the Materialabscheideeinrichtung is adapted for in the micro channel ( 22 ) another metal ( 20 ) for regrowth of the hair element ( 14 ) to be electrodeposited from below; • an ejection or ejection device ( 24 ) for ejecting or pushing out the regrowing hair element ( 14 ) by the Growth channel ( 30 ), where the growth channel ( 30 ) is formed such that the hair element ( 14 ) at an exit opening ( 26 ) of the microsystem area ( 28 ) from the growth channel ( 30 ) comes to the outside, • a force sensor for measuring the hair element ( 14 ) acting force, which has a torque on the hair element ( 14 ) and thereby at the outlet opening ( 26 ) causes a curvature. Artificial hair cell sensor ( 32 ) with • two separate microchannels ( 46 . 48 ); • one with the microchannels ( 46 . 48 ) related growth channel ( 40 ); • one in the growth channel ( 40 ) and on a microsystem surface of the hair cell sensor ( 34 ) from the growth channel ( 40 ) upwardly projecting hair element ( 14 ); • an integrated micro-production facility ( 34 ), which has a material hardening device, wherein the material hardening device is adapted to use two starting materials ( 42 . 44 ) separated by the microchannels ( 46 . 48 ) of a growth zone ( 50 ) below the hair element ( 14 ) liquid, the starting materials ( 42 . 44 ) form a two-component system which hardens chemically, whereby the hair element ( 14 ) grows from below; • an ejection or ejection device ( 36 ) for ejecting or pushing out the regrowing hair element ( 14 ) through the growth channel ( 40 ), where the growth channel ( 40 ) is formed such that the hair element ( 14 ) at an exit opening of the microsystem area from the growth channel ( 40 ) comes to the outside, • a force sensor for measuring the hair element ( 14 ) acting force, which has a torque on the hair element ( 14 ) and thereby causes a curvature at the outlet opening.

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